Purple yam (Dioscorea alata L.) belonging to the herbaceous vine plants, dioscorea genus, Dioscorea subject and one kinds of edible plants. It’s Native to tropical Asia, purple yam is plants grown under a suitable short sunshine growth environment, is a kind of thermophilic plants, mainly temperate zone in China's southern provinces. We performed different cultivation methods on Yield and variety comparison test for planting on north area of China. To choicing the different position of the yam block, shuch as the top and the middle block and different weight of harvested. Then average per mu 2600 strains were calculated and counting the per mu yield. The growth of the top position of the yam is better than the middle of plant growth. The yield of the top position is higher than the same weight of tubers of the middle position. The best kind of potato weight should be between 100-150g, so that it can reduce costs, but also have a considerable income.